When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
There are two different sizes for those brackets I've noticed in my experience of working on them. Whatever bolt is the biggest that will fit in the hole is what you want. I believe there are two sizes on the brackets themselves, as well as two differently size holed radius arm brackets. I'd take the bracket with you to the hardware store and see what fits.
I have the Skyjacker extended radius arms on my 92 F150. The bolts that came in the kit for the brackets are 7/16 x 1 1/2" fine thread and are grade 8. Try your local speed shop, they should have a selection of grade 5 and grade 8 hardware.
Big Brown Ford
1992 F150 XLT Supercab 4x4, 5.0
6" lift, 33's winter/ 35's summer
Superlift TruSpeed Sensor
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.